In the game, players choose one of six character classes – Barbarian, Crusader, Demon Hunter, Monk, Witch Doctor or Wizard (with the Crusader being unavailable unless the player has purchased the expansion pack, Diablo III: Reaper of Souls) – and are tasked with defeating the Lord of Terror, Diablo.

The expansion packDiablo III: Reaper of Souls was released for the Windows and OS X editions of the game on March 25, 2014. For consoles the expansion pack content was released as part of the Diablo III: Ultimate Evil Edition version. It was released for the PlayStation 4, Xbox One, PlayStation 3, and Xbox 360 on August 19, 2014. Diablo III: Ultimate Evil Edition includes the original console version of Diablo III and Diablo III: Reaper of Souls expansion pack.[9]

Diablo III's inventory and HUD retain a feel similar to that found in earlier games in the series, including a viewpoint reminiscent of the isometric view of Diablo III's predecessors. The inventory has sixty slots for items. Armor and weaponry each occupy two slots and all other items each occupy one slot.[10] It can also be expanded to include details about the character's attributes.

Much like in Diablo and Diablo II, the quality and attributes of equipment are randomized. In addition to base stats (such as damage and attack speed for weapon or armor points on armor), higher-quality items have additional properties, such as extra damage, attribute bonuses, bonuses to critical hit chance or sockets (which allow items to be upgraded and customized by adding gems for various stat bonuses). Magic-quality items have 1 to 3 random properties, rare-quality items have 4 to 6 random properties and legendary-quality items typically have 6 to 8 properties with varying degrees of randomness (for example, the Mempo of Twilight, a legendary helm, always has a socket, bonuses to elemental resistance, attack speed and life, a bonus to either Intelligence, Dexterity or Strength, and one additional random property, however the magnitude of these bonuses varies from item to item), and set items are a subtype of legendary items which provide additional, cumulative bonuses if multiple items from the same set are simultaneously equipped. Higher level monsters tend to drop higher level items, which tend to have higher base stats and bonuses.[11]

The proprietary engine incorporates Blizzard's custom in-house physics, and features destructible environments with an in-game damage effect. The developers sought to make the game run on a wide range of systems without requiring DirectX 10.[12]Diablo III uses a custom 3D game engine[13] in order to present an overhead view to the player, in a somewhat similar way to the isometric view used in previous games in the series.[12] Enemies utilize the 3D environment as well, in ways such as crawling up the side of a wall from below into the combat area.[14]

As in Diablo II, multiplayer games are possible using Blizzard's Battle.net service,[15] with many of the new features developed for StarCraft II also available in Diablo III.[12] Players are also able to drop in and out of sessions of co-operative play with other players.[16] Unlike its predecessor, Diablo III requires players to be connected to the internet constantly due to their DRM policy, even for single-player games.[17]

An enhanced quest system, a random level generator, and a random encounter generator are used in order to ensure the game provides different experiences when replayed.[18]

Unlike previous iterations, gold can be picked up merely by touching it, or coming within range, adjusted by gear, rather than having to manually pick it up. One of the new features intended to speed gameplay is that health orbs drop from enemies, replacing the need to have a potion bar, which itself is replaced by a skill bar that allows a player to assign quick bar buttons to skills and spells; previously, players could only assign two skills (one for each mouse button) and had to swap skills with the keyboard or mousewheel. Players can still assign specific attacks to mouse buttons.[19]

Skill runes, another new feature, are skill modifiers that are unlocked as the player levels up. Unlike the socketable runes in Diablo II, skill runes are not items but instead provide options for enhancing skills, often completely changing the gameplay of each skill.[20] For example, one skill rune for the Wizard's meteor ability reduces its arcane power cost, while another turns the meteor to ice, causing cold damage rather than fire.

As in Diablo II, Diablo III gives players the choice to make hardcore characters.[21] Players are required to first level up a regular character to level 10 before they have the option to create new Hardcore characters.[22] Hardcore characters cannot be resurrected; instead they become permanently unplayable if they are killed. Hardcore characters are separately ranked, and they can only form teams with other hardcore characters. After dying, the ghost of a hardcore character can still chat, the name still shows up in rankings, but the character cannot return to the game.[23]

Artisans are non-player characters (NPCs) who sell and craft. Two types of artisans can be introduced by completing a quest for each: Haedrig Eamon the Blacksmith and Covetous Shen the Jeweler. The Reaper of Souls expansion introduced the Mystic artisan, who can replace individual item enchantments and change the physical appearance of items. Artisans create items using materials the player can gather by scrapping acquired items and reducing them to their component parts. These materials are used to create items which will have random bonuses. Unlike Diablo II, rare and magic items can be enhanced, not just basic weaponry and armor. Crafting can also be used to train and improve the skills of the artisans rather than create new items. When artisans gain new levels, their shop reflects their higher skill level. The process of salvaging items into materials also makes inventory management easier. Blizzard stated that this crafting system was designed so that it would not slow down the pace of the game.[24]

Followers are NPC allies that can accompany the player throughout the game world. There are three followers in Diablo III: Kormac the Templar, Lyndon the Scoundrel and Eirena the Enchantress, who each possess their own skills and background.[25] As followers fight alongside the player, they gain new experience, skills, and equipment as they level up. Only one follower accompanies the player at a time, creating a gameplay strategy decision. Originally, followers were only going to appear in Normal mode; however, Jay Wilson stated at BlizzCon 2011 that followers would continue to be usable in later difficulty levels.[26] Followers do not appear in co-op games nor against Diablo, as he will trap them in a cage of metal bones.

On August 1, 2011, it was reported that Diablo III would feature two types of auction houses; one where players spend in-game gold and another where players could buy or sell virtual items for real-world money.[27] The real-money auction house was not available in Hardcore mode.[28]

Prior to release, Blizzard stated that nearly everything that drops on the ground, including gold, could be traded with other players either directly or through the auction house system. Aside from certain bound on account items, such as the Staff of Herding needed to access the Whimsyshire easter egg, Blizzard stated there would be very few items that would be bound to a particular character and therefore un-tradable.[28]

In order to get rated in South Korea, Blizzard had to remove the real-money auction house from the Korean release of the game as the auction house violated Korean anti-gambling laws.[29]

In the gold-based auction house, a flat fee of 15 percent was taken from the final sale price of an auction. The real-money auction house fees were US$1, €1 or £1 (or equivalent) for equipment (weapons and armor) and 15 percent fee for commodity auctions, which included items like crafting materials, blacksmith and jewelcrafting plans, and gold exchange. There was an additional 15 percent "cashing-out" fee from proceeds gained selling items in the real-money auction house.[30]

While the gold-based auction house was available to any player regardless of which region they play in, the real-money auction was restricted to players on their home region. If they used the global play function to play in a different region, they would not be able to access the real-money auction house.[31] The real money auction house was opened on June 12, 2012 (June 15 in the Americas).

In March 2013, former Diablo III game director Jay Wilson stated that he felt the existence of the auction houses "really hurt" the game. "I think we would turn it off if we could," Wilson said during his talk. But the problem is "not as easy as that."[32][33][34]

On September 17, 2013, Blizzard stated that both the gold and real-money auction houses would be shut down on March 18, 2014.[35] On March 18, 2014, Blizzard closed all the auction houses in Diablo III. Players had until June 24, 2014 to claim gold and items from the completed tab on the auction house interface.[36]

Player versus player combat (PvP) was added to Diablo III in a limited form with the 1.0.7 patch, in February 2013. The Brawling system provides a simple free for all area where between two and four characters can fight and defeat each other as long as they like, but without any scores or damage being tracked.[37] Players can participate by choosing from their existing characters, with access to all of the gear and skill they have gathered from playing the game in single-player or cooperative mode.

PvP content for Diablo III had been discussed throughout the game's development, but on March 9, 2012, Blizzard announced that PvP had been delayed and would not be included with the game's release.[38] Lead designer Jay Wilson said in a post on Battle.net that the PvP Arena system would arrive in a post-release patch; it would include multiple Arena maps with themed locations and layouts, PvP-centric achievements, and a quick and easy matchmaking system. "We'll also be adding a personal progression system that will reward you for successfully bashing in the other team's skulls", Wilson added.

On December 27, 2012, Blizzard announced that the previously mentioned Team Deathmatch or Arena mode was cancelled, because it did not have enough depth. Instead a simple PvP system would be added for the time being.[39] That PvP mode was initially named Dueling, and was renamed to Brawling before release.[40] Although the PvP systems initially outlined were not released, Blizzard stated that they will add other full-featured PvP systems in a future free content patch. In a May 2013 interview, Diablo III developer Wyatt Cheng stated that the development team was looking to see how the Brawling PvP evolves, while they "continue to work on figuring out something more objective-based."[41]

The five original character classes of Diablo III. From left to right: Wizard, Witch Doctor, Demon Hunter, Barbarian, and Monk.

Character creation screen with the Demon Hunter selected

There are five available character classes from Diablo III and one from the Reaper of Souls expansion, for a total of six character classes; a seventh will be added in 2017.[42][43][44] In the previous two games, each class had a fixed gender, but in Diablo III players may choose the gender they would like to play.[14]

The Witch Doctor is a new character reminiscent of the Diablo II necromancer but with skills more traditionally associated with shamanism and voodoo culture. The witch doctor has the ability to summon monsters, cast curses, harvest souls, and hurl poisons and explosives at their enemies. To power spells the Witch Doctor uses Mana, which regenerates slowly.[45]

The Barbarian previously appeared in Diablo II, and has a variety of revamped skills at its disposal based on incredible physical prowess. The barbarian is able to whirlwind through crowds, cleave through swarms, leap across crags, crush opponents upon landing, and grapple-snap enemies into melee range. The resource used by the barbarian is fury, which is generated through attacking enemies, getting attacked by enemies, and using certain abilities. Fury is used for certain strong abilities and degenerates over time.[46]

The Wizard is a version of the sorceress from Diablo II or the sorcerer from Diablo. The Wizard's abilities range from shooting lightning, fire and ice at their enemies to slowing time and teleporting past enemies and through walls. Wizards fuel their spells with arcane power, which is a fast regenerating power source.[47]

The Monk is a melee attacker, using martial arts to cripple foes, resist damage, deflect projectiles, attack with blinding speed, and land explosive killing blows. Monk gameplay combines the melee elements of Diablo II's assassin class with the "holy warrior" role of the paladin. Blizzard has stated that the monk is not related in any way to the monk class from the Sierra Entertainment–made Diablo: Hellfire expansion.[48] The monk is fueled by spirit, which has defensive purposes and is slowly generated through attacking, though it does not degenerate.[49]

The Demon Hunter combines elements of Diablo II's amazon and assassin classes. Demon hunters use crossbows as their main weapon and can also throw small bombs at enemies. The demon hunter is fueled by both discipline and hatred: Hatred is a fast regenerating resource that is used for attacks, while discipline is a slow regenerating resource used for defensive abilities.[50]

The Crusader is a Reaper of Souls expansion character. The crusader has a variety of combat skills at its disposal based on physical prowess, and typically wields a shield and an associated weapon (typically a flail). The crusader is able to ride a horse and strike enemies, shield bash enemies, summon a blessed hammer that circles around the crusader, leap into the air and come crashing down on enemies, have lightning strike foes from the sky, taunt enemies, hurl shields and hammers at enemies, and many more. The resource used by the crusader is wrath, which is generated through attacking enemies, getting attacked by enemies, and using certain abilities.

The Necromancer is a death-themed spellcaster that will be made available as downloadable content on PC and consoles sometime in 2017. Described as a "reimagining" of the previous incarnation seen in Diablo II, the necromancer specializes in summoning skeletal minions and using blood magic to power their offensive abilities.[44]

The Archivist class was presented on April 1, 2009, following in Blizzard's April Fool's Day joke tradition.[51]

The game takes place in Sanctuary, the dark fantasy world of the Diablo Series, twenty years after the events of Diablo II. Deckard Cain and Leah are in Tristram Cathedral (the same cathedral that was the setting of Diablo) investigating ancient texts regarding an ominous prophecy. A mysterious star falling from the sky strikes the Cathedral, creating a deep crater into which Deckard Cain disappears.

The protagonist arrives in the town of New Tristram to investigate the falling star which struck the cathedral, which is now emanating risen undead. The protagonist accompanies Leah to the cathedral in order to rescue Cain from the crater into which he fell. After rescuing Cain, the protagonist learns that the only way to the fallen star is to defeat King Leoric, the former ruler of Tristram known now as the 'Skeleton King'. Cain informs the protagonist that Leoric's crown must be recovered to defeat him, and the protagonist searches for Leoric's crown with the aid of Haedrig Eamon, the blacksmith of New Tristram. After recovering the crown, the protagonist returns to the cathedral where he/she eventually encounters and rescues Kormac, a warrior of the Templar order who has been taken captive by members of a cult known as the Dark Coven. Together, they defeat Leoric and find a stranger where the fallen star landed. The stranger's only memory is of a sword that shattered into three pieces as he fell.

The protagonist recovers the sword pieces from the Khazra Den and the Drowned Temple, opposed by the witch Maghda, leader of the Dark Coven. Maghda, however, recovers the third piece before the protagonist does and attempts to force Cain to repair the sword. Leah, however, kills the cultists with a surge of magical power, forcing Maghda to kill Cain and flee with the stranger. Cain, before dying, repairs the sword and tasks the protagonist with returning it to the stranger, revealing that both the sword and the stranger are angelic. The protagonist pursues Maghda into the bowels of King Leoric's dilapidated torture chambers underneath his manor, rescuing the stranger and returning to him his sword after a violent fight with the Butcher, a powerful demon. The stranger's memories are recovered, and it is revealed that he is the Archangel Tyrael, the Aspect of Justice. Disgusted with his fellow angels' unwillingness to protect humanity from the forces of Hell, Tyrael casts aside his divinity to become a mortal and warn Sanctuary about the arrival of the demon lords Belial (Lord of Lies) and Azmodan (Lord of Sin).

The protagonist, Leah, and Tyrael travel to the city of Caldeum. The protagonist leaves to track down Maghda at Alcarnus as per orders from Asheara, commander of the Iron Wolves (returning from Diablo II), while Leah and Tyrael search for evidence of Belial in the city sewers. The protagonist first encounters a young Enchantress who introduces herself as Eirena, who hails from a different era. With Eirena's help, the protagonist finds and stops cultists from channeling an illusion by halting their progress. Continuing on, the protagonist reaches the Khasim Outpost, finding that Belial's serpent demons have imprisoned and replaced the true guards. Freeing Captain Davyd and his men, the protagonist reclaims the Khasim Outpost from the serpent demons and is given access to Alcarnus. After freeing the prisoners, the protagonist fights Maghda in her lair and destroys her, avenging Cain, then returns to Caldeum to rescue Leah from the grasp of the Imperial Guards. Gaining an audience with the young Emperor of Caldeum, Hakan II, the protagonist is blamed for the chaos at Alcarnus, and the Emperor orders the protagonist's death and that Leah be brought to him, forcing the protagonist to escape the palace. Escaping to the sewers, Leah reveals that her mother, Adria (the witch of Tristram from the original game) is still alive. The protagonist aids Leah in rescuing Adria from the city's sewers.

Adria reveals that the key to stopping the forces of Hell is the Black Soulstone. Crafted by the deranged warlock Zoltun Kulle, it has the power to trap the souls of the seven Lords of Hell and destroy them forever. Leah explains that Kulle was slain by the Horadrim before he could put the finishing touches on the stone, and that his severed head was sealed off in the lush Dahlgur Oasis. Adria instructs the protagonist to find the warlock's head in the oasis if the Soulstone is to be retrieved. After the head is retrieved, Leah revives the ghost of Zoltun Kulle, and Tyrael instructs him to activate the Black Soulstone. Kulle states that two vials of his blood hidden by the Horadrim in the Desolate Sands are needed to reach the stone. Leah decides to accompany the protagonist whilst putting the warlock's head in the protagonist's packs. After recovering the two vials of blood, the protagonist ventures into Kulle's archives in search of his body, while Leah prepares the ritual to bring Kulle back. After Kulle is brought back to life, the protagonist is then led into the archive's inner sanctum where the Black Soulstone is located, but is forced to defeat Kulle when the resurrected warlock attempts to take the soulstone for himself[citation needed]. Upon returning to Caldeum, the protagonist finds the city under attack by Belial's forces. Leah and Adria fight their way to the palace with the protagonist, revealing Belial as having taken the form of the Emperor to deceive them, and eventually defeat him. Leah then traps Belial's soul within the Black Soulstone, freeing Caldeum, after which she has a vision of the demon lord Azmodan, who is invading Sanctuary from the crater of Mount Arreat (destroyed by Tyrael in Diablo II: Lord of Destruction) in order to retrieve the Black Soulstone and empower himself, becoming the Prime Evil.

The protagonist travels to Bastion's Keep with Tyrael, their followers, Leah and Adria only to find it under attack by Azmodan's army. Tyrael instructs the protagonist to aid the defenders, lighting the signal fires on the keep's walls, and raising the catapults. With that done, the protagonist enters the stronghold, where Azmodan's forces have breached the lower levels, defeating the demon Ghom, the Lord of Gluttony. The protagonist then takes to the battlefield, destroying Azmodan's siege weapons and traveling to the crater of Mount Arreat. Tyrael assists the protagonist in reaching the demonic gate protecting the crater, and destroys it with his sword, El'druin. After a gruesome battle with a huge Siegebreaker Assault Beast, the protagonist traverses the depths of Arreat's inner core, destroying the Sin Hearts, which empower Azmodan and his armies. Azmodan's consort Cydaea, the Maiden of Lust, attempts to protect the hearts, but is defeated by the protagonist, who then confronts and defeats Azmodan. Leah seals Azmodan's soul within the Black Soulstone. With all seven Lords of Hell trapped within the stone, Tyrael states that the Eternal Conflict between Heaven and Hell will be ended if the stone is destroyed. The protagonist returns to Bastion's Keep, but finds that Adria has betrayed them. Adria reveals she has been serving Diablo from the beginning, and that Leah's father is Leoric's son Aidan, the Dark Wanderer (the Warrior player character from the first game and Diablo's reincarnate body in Diablo II), who was possessed by Diablo. Adria uses the Black Soulstone to resurrect Diablo while forcing Leah to serve as his vessel. With all the souls of the Lords of Hell now within him, Diablo becomes the Prime Evil, and begins an assault on the High Heavens.

The protagonist arrives in the High Heavens to find that it is already under attack. Imperius, the Aspect of Valor, blames the protagonist and Tyrael for their downfall, causing Tyrael to give in to despair. On the other hand, the protagonist remains determined to fight, and defeats the demon Iskatu. The protagonist then meets Itherael, the Aspect of Fate, who instructs him to rescue Auriel, the Aspect of Hope, from Rakanoth, the Lord of Despair, in the Library of Fate. After rescuing Auriel and returning hope to the forces of Heaven, the protagonist is then instructed by Auriel to close the Hell Rifts. After this is done, the protagonist finds Tyrael, who has overcome his despair. Together, they attempt to stop Diablo from reaching the Crystal Arch, the source of power for the forces of Heaven, but not before a brawl with Izual, Tyrael's corrupted former lieutenant. After a long and fierce battle, Diablo is defeated and his physical manifestation is destroyed. The Black Soulstone is shown falling from the High Heavens, still intact. After the battle, Tyrael decides to rejoin the Angiris Council as the new Aspect of Wisdom, but remains a mortal, dedicated to building a permanent alliance between angels and humans.

Development on Diablo III began in 2001 when Blizzard North was still in operation, and the game was first announced on June 28, 2008, at the Blizzard Worldwide Invitational in Paris, France.[18] The original artistic design differed from that shown at Blizzard Worldwide Invitational 2008 demonstration, and had undergone three revisions before reaching the standards felt necessary by the team behind Diablo III.[citation needed] It was announced that the game would be simultaneously released on both Windows and Mac OS X platforms,[18] and would require a constant internet connection to play, even for single-player mode.[52]

The proprietary engine incorporates Blizzard's custom in-house physics, a change from the original usage of Havok's physics engine,[53] and features destructible environments with an in-game damage effect.

Bobby Kotick from Activision announced in February 2012, that Diablo III would not launch in the 1st quarter of 2012; a slide show presentation at Activision's quarterly financial report listed the game's launch sometime in Q2 of 2012, and the release date of May 15, 2012, was announced on March 15, 2012.[4]

On May 9, 2011, Blizzard announced that Diablo III was expected to be released for external beta testing in Q3 of 2011.[56] On September 7, 2011, Blizzard community manager Bashiok confirmed the start of the closed public beta test of the game with limited external testing by employees and their families. Testers were not restricted by a non-disclosure agreement (NDA) i.e. every participant would be free to show, share, or talk about any portion of the beta content.[57] On September 20, 2011, Blizzard announced through their Diablo III site that the closed beta test portion of the game through invites, promotions and giveaways had begun. On October 22, 2011, at BlizzCon, Diablo III game director Jay Wilson announced during an open Q&A that a new wave of beta invitations would be sent after an upcoming patch. Blizzard announced on April 19, 2012, that there would be an open beta weekend for the game, starting on April 20, 2012, and ending the morning of April 23.[58] The closed beta ended on May 1, 2012.

The content available in the beta included the possibility to try all 5 character classes in the first act up to the Skeleton King encounter. The players were also able to try various in-game features such as crafting through the blacksmithing NPC, the auction house, hosting and joining public games as well as earning achievements.[59]

The beta website made references that measures would be in place to prevent future cheating.[60]

On June 11, 2012, it was announced at Apple's 2012 WWDC keynote that native Retina display support will be coming to Diablo III.[61] The following day, a Blizzard representative confirmed via the official Battle.net forums Apple's statement, the ongoing work by the developer on the optimization of the game engine for its rendering on the Retina display (and technically on other similar future high-density monitors) and that this optimization will be mainly for aesthetic purposes.[62]

Patch 1.0.4 introduced the paragon leveling system. After reaching the level cap of 60, characters continue to accumulate experience points, gaining paragon levels (up to a cap of 100), each of which provides a bonus to core stats (making characters more powerful and durable) and magic find and gold find (increasing the quantity and average quality of loot drops).[63]

Patch 1.0.5 expanded the difficulty settings with the addition of the Monster Power system. In addition to the Normal/Nightmare/Hell/Inferno difficulty system, players can also set Monster Power at any level from 0 to 10, with each level of Monster Power increasing the damage, health points, experience point yield and loot drop rates beyond the base value for a given difficulty tier.[64]

The first PvP addition to the game was in February 2013, as part of patch 1.0.7; a simple free-for-all system called "Brawling" and multiple item crafting options.[37]

On February 25, 2014, patch 2.0.1 was released, introducing extensive changes in preparation for the Reaper of Souls expansion, which was itself released on March 25.

For Diablo's 20th anniversary, it was announced during BlizzCon 2016 that Diablo III would receive a free patch called The Darkening of Tristam that would recreate the original game. The patch will contain a 16-level dungeon, four main bosses from the 1996 version and special graphics filters and 8-directions limited movement like the original game. Tha patch is scheduled to release one week after the event, which happened on November 4, 2016.[65][66]

On January 10, 2012, Blizzard community manager Bashiok tweeted "Yup. Josh Mosqueira is lead designer for the Diablo III console project"[67] however a Blizzard spokesperson later clarified that Bashiok's tweet was only "intended as a confirmation that Blizzard is actively exploring the possibility of developing a console version of Diablo III," adding, "This is not a confirmation that Diablo III is coming to any console platform."[68]

At Sony's Press Conference on February 20, 2013, Chris Metzen announced that Diablo III would release on both PlayStation 3 and PlayStation 4.[2]Activision Blizzard stated in their first-quarter 2013 earnings report, that the PlayStation 3 version of Diablo III would be released in 2013.[69] On June 6, 2013, Blizzard announced that both the PlayStation 3 and Xbox 360 port of the game would be released on September 3, 2013.[3] A PS3 version of the game was published and localized by Square Enix in Japan, released there on January 30, 2014.[70]

In August 2013, Diablo III developers stated that they had started on the PlayStation 4 development of the game, titled Diablo III: Ultimate Evil Edition, and were looking at how to best utilize the new features of the PS4 controller, such as the TouchPad and the Share button. They are hopeful that characters from the PS3 version of Diablo III will be able to play directly on the PS4.[71] In May 2014, Blizzard announced that Diablo III: Ultimate Evil Edition would be released on August 19, bringing the game to the PlayStation 4, Xbox One, PlayStation 3, and Xbox 360.[9] The game will run at 1080p on PlayStation 4 and, while it was initially announced to run at 900p on Xbox One, a day one patch will enable it to run at 1080p.[72][73] The consoles versions of Reaper of Souls added several new features exclusive to it, including the Nemesis System which will send a boss into your game that will hunt down your character specifically. If you defeat the boss you are awarded with a higher chance at legendary items, but if it kills your character it will come back, but stronger and also be transferred to another player on your friends list if you are online.

Diablo III was released on May 15, 2012. Players had the options to buy one of two retail boxed versions, a standard edition and collector's edition, or could also pre-order directly from Battle.net and download the installer in advance. On May 14, 2012, players who bought the downloadable version from Battle.net could install the rest of the game including patches.[74] On May 15, 2012, the retail version could be bought from stores doing midnight launches such as GameStop. The Diablo III Battle.net servers went live at this time and people who downloaded the game could begin playing. Initially the launches were hindered by heavy server load with many users getting various errors, including the error 37 which reads; "The servers are busy at this time. Please try again later". These issues made the game unplayable for those affected, while some others experienced in-game bugs.[75][76] Despite assurances from Blizzard that the problems leading to the connection errors during Diablo III's launch had been resolved, Eurogamer reported on May 31, 2012, that these errors were still ongoing, and had reappeared after patch 1.0.2 was released for the game. Many fans complained that the ongoing problems had caused them to lose their hardcore (permanent death) characters.[77]

In South Korea, players waited up to 36 hours to purchase the collector's edition.[78]

The release was also the source of a minor controversy in Australia when retailer Game went into voluntary administration the day before the release, and so was unable to honor pre-orders or offer refunds.[79] In response to this, Blizzard Entertainment offered affected customers credit in purchasing the digital version of the game.[80]

On April 23, 2015, the game was released in China as it was approved by the Ministry of Culture.[81] It used to be sold under the name "Big Pineapple" (大菠萝 Dɑ Boluo) which sounds similar to Diablo in Mandarin Chinese in order to dodge the sales ban.[82]

Starting at BlizzCon in October 2011, Blizzard offered an "annual pass" for World of Warcraft, where players who signed up for a 12-month subscription to that game received a free digital copy of Diablo III once released, as well as guaranteed beta access for the Mists of Pandaria expansion to World of Warcraft and a special Diablo-inspired mount called Tyrael's Charger in World of Warcraft.[83]

A demo version of the game, called the Starter Edition, was released simultaneously with the full release. It provides a limited introduction to the game where players can complete Act 1 up to the Skeleton King boss encounter with a level cap of 13. Originally after Diablo III's release the Starter Edition was only available through a guest pass code, which was included with the boxed versions of the game. Players have the option to upgrade to the full game through their Battle.net accounts.[84] The Starter Edition became available to all users a few months after release on August 15, 2012.[85]

Russell Brower was the primary composer of the music for Diablo III. Additional music was composed by Derek Duke, Glenn Stafford, Joseph Lawrence, Neal Acree, Laurence Juber & Edo Guidotti. When composing for the orchestra, Brower tried to respect the Wagnerian style from the expansion to the second game in the series, Lord of Destruction.[86] The Overture is considered the main theme of the game and it has been performed by the Eminence Symphony Orchestra, and was released on iTunes in 2009, as a single.[87] A similar composition was used in the cinematic teaser trailer of the game. The Tristram theme from the first Diablo, also used in the second game, is present in Diablo III with some changes.[citation needed]. Irish choral ensemble Anúna also feature on the soundtrack. Brower stated that "Working somewhat against conventional expectations, Hell is a beautiful and seductive sound, provided by Dublin’s uniquely astounding choral group ANÚNA".[88] A full soundtrack was released on iTunes on May 15, 2012 (the same day the game was released), as well as part of the Collector's Edition of the game.

On August 21, 2013, it was announced at the German games fair Gamescom that Diablo III: Reaper of Souls would be the first expansion for Diablo III. It features the fallen angel of wisdom Malthael as the expansion's main villain and is set in the city of Westmarch, which takes inspiration from many Gothic medieval locations. The expansion includes a new hero called the Crusader, an increased level cap to level 70, major improvements to loot drops including the ability to change item stats using an enchanting system, the ability to change the look of an item using transmogrification, and an improved Paragon leveling system which is account-wide and does not have a level cap.[89]

Reaper of Souls was released on March 25, 2014, for the Windows and OS X versions of Diablo III.[90] The expansion pack content was released as part of the Diablo III: Ultimate Evil Edition version for consoles on August 19 for the PlayStation 4, Xbox One, PlayStation 3, and Xbox 360.[9] That edition expanded the base Diablo III game on the PlayStation 3 and Xbox 360, and brought the game for the first time to the PlayStation 4 and Xbox One.

Diablo III has received positive reviews from critics, attaining scores of 88% and 88/100 on aggregate review websites GameRankings and Metacritic respectively.[93][97]

GamesRadar was positive about the game's opening act and its nods to past Diablo games saying "we liked what we saw."[111]

IGN was positive about the new skill system stating "Instead of gameplay like Diablo II, where I often regretted how I allotted my ability points, Diablo III encourages experimentation and finding out exactly what works for your play-style. It's a vastly superior way to handle character abilities", and praised the overall gameplay, stating "the new systems really do make it a lot easier to enjoy Diablo III".[112] IGN further praised the game's new gameplay design, in particular the rune and loot systems, the randomly generated levels and the game's enjoyable unpredictability. It stated the game's feel is quite intuitive and also praised the game's sound and voicing.[113]

Rock, Paper, Shotgun gave mixed commentary during the game's beta period, praising the actual game itself by stating that it is much more direct than its predecessors and intuitive in its interface. However, it said the playing experience is spoiled due to lag in single-player mode caused by a lack of an offline single-player mode.[114] Following the game's release, it reaffirmed its displeasure at the always-online DRM and offered a mixed opinion that the game was enjoyable but added "nothing new" to its genre.[115]

Erik Kain, a Forbes contributing writer, stated that the requirement to remain online is not necessary for single-player mode and that Blizzard is abusing its position as a "juggernaut" and is setting a worrying precedent for the gaming industry.[8] In response to questions about the lack of offline single-player, Diablo III senior producer Alex Mayberry said, "Obviously StarCraft II did it, World of Warcraft authenticates also. It's kind of the way things are, these days. The world of gaming is not the same as it was when Diablo II came out."[116]

Gaming Blend supported the game's fanbase (referring to the user ratings on Metacritic and Amazon) and rejected counter-criticisms of the community. It claims that the gaming industry at large is far too defensive of production companies' actions, to the point of accepting backward steps in game availability. William Usher, the article's author said, "Journalists should have been acknowledging consumer distaste rather than fueling it with pro-corporate pandering."[117]

While Gaming Blend disliked the always-online DRM, it did give the game a positive review. It stated the game includes interesting opportunities for experimentation and has great appeal for replaying over and over. The review concluded the game is "smooth and entertaining."[118] A GameArena critic questioned how Blizzard managed to "fail so spectacularly at creating reliable networking for Diablo 3" before going on to point out the lack of competitive multiplayer.[119]

Many users criticized the art direction as it was considered too bright and colourful in contrast to the darker atmosphere of the previous releases. This led to petitions demanding Blizzard to change the design. The lead producer responded to these criticisms and explaining the design choices by stating that "We feel that color actually helps to create a lot of highlights in the game so that there is contrast." He also highlighted that unlike the previous games, the players explore outdoors.[120]

The Black Soulstone footage won the 'Outstanding Visual Effects in an Animated Commercial or Video Game Trailer' award from the Visual Effects Society.[121][122]

Before its release, Diablo III broke several presale records and became the most pre-ordered PC game to date on Amazon.com.[123] Activision Blizzard reported that Diablo III had broken the one-day PC sales records, accumulating over 3.5 million sales in the first 24 hours after release and over 6.3 million sales in its first week, including the 1.2 million people who obtained Diablo III through the World of Warcraft annual pass.[124] On its first day, the game amassed 4.7 million players worldwide, an estimate which includes those who obtained the game via the World of Warcraft annual pass.[124] In its 2012 second quarter report, Diablo III was reported to have pushed Activision Blizzard's expectations and as of July 2012, more than 10 million people had played the game.[125]Diablo III remains the fastest selling PC game to date, and also one of the best-selling PC video games. As of the end of 2012, it had sold more than 12 million copies,[7] and as of March 2013, Blizzard stated that Diablo III had around 1 million daily players, with 3 million unique players each month.[126] As of May 2013, Diablo III had been played by 14.5 million unique players, according to Blizzard's released statistics.[127] As of February 2014, the game had sold 15 million copies across all platforms.[128] As of June 30, 2014, Diablo III and Reaper of Souls had combined sales worldwide of more than 20 million copies.[129] As of June 30, 2015, the game had sold, along with Reaper of Souls, 30 million units.[130]

On May 28, 2012, Blizzard Entertainment's offices in South Korea were raided by the Fair Trade Commission amid allegations that the company had breached consumer rights laws, including suspected violations of Korea's law on electronic commerce and commercial contracts. Players in Korea requested refunds from Blizzard based on their inability to play Diablo III, but Blizzard cited the terms of sale and refused to grant these requests. Hundreds of gamers filed formal complaints with the FTC,[131][132][133] and in June 2012 Blizzard started offering players full refunds.[134]

On June 15, 2012, French consumers group UFC Que Choisir announced that it had received 1,500 complaints in four days regarding connectivity issues with Diablo III.[135] As a result of this, the organization asked Blizzard Entertainment to provide a permanent solution by June 30, 2012, and to "communicate completely and transparently about problems encountered in due time". They also requested that gamers be given reimbursement for any troubles they may have encountered. In addition, they asked the French government to take a closer look at games with online-only DRM.[136] On June 28, Blizzard replied to the Que Choisir that the box for Diablo III clearly labelled that a high-speed internet connection was required and that most of the stability issues had been fixed.[137]

The German Federation of Consumer Organizations threatened legal action if Blizzard did not respond to complaints about Diablo III's lack of clear information on the German version of the box regarding the always online requirement and lack of ability to resell the digital game.[138][139]